5. Pyelitis.--In pyelitis the urine is slightly acid, and contains a small or moderate amount of pus, together with many spindle and caudate epithelial cells. Pus-casts may appear if the process extends up into the kidney tubules (see Fig. 62). Albumin is always present, and its amount, in proportion to the amount of pus, is decidedly greater than is found in cystitis. [Illustration: FIG. 62.--Sediment from calculous pyelitis: numerous pus-corpuscles, red blood-corpuscles, and caudate and irregular epithelial cells; a combination of hyaline and pus-cast; and a few uric-acid crystals (Jakob).] 6. Cystitis.---In _acute_ and _subacute_ cases the urine is acid and contains a variable amount of pus, with many epithelial cells from the bladder--chiefly large round, pyriform, and rounded squamous cells. Red blood-corpuscles are often numerous. In _chronic_ cases the urine is generally alkaline. It is {137} pale and cloudy from the presence of pus, which is abundant and settles readily into a viscid sediment. The sediment usually contains abundant amorphous phosphates and crystals of triple phosphate and ammonium urate. Vesical epithelium is common. Numerous bacteria are always present (see Fig. 63). [Illustration: FIG. 63.--Sediment from cystitis (chronic): numerous pus-corpuscles, epithelial cells from the bladder, and bacteria; a few red blood-corpuscles and triple phosphate and ammonium urate crystals (Jakob).] 7. Vesical Calculus, Tumors, and Tuberculosis.--These conditions produce a chronic cystitis, with its characteristic urine. Blood, however, is more frequently present and more abundant than in ordinary cystitis. With neoplasms, especially, considerable hemorrhages are apt to occur. Particles of the tumor are sometimes passed with the urine. No diagnosis can be made from the presence of isolated tumor cells. In tuberculosis tubercle bacilli can generally be detected. 8. Diabetes Insipidus.--Characteristic of this disease is the continued excretion of very large quantities of pale, watery urine, containing neither albumin nor sugar. The {138} specific gravity varies between 1.001 and 1.005. The daily output of solids, especially urea, is increased. 9. Diabetes Mellitus.--The quantity of urine is very large. The color is generally pale, while the specific gravity is nearly always high--1.030 to 1.050, very rarely below 1.020. The presence of glucose is the essential feature of the disease. The amount of glucose is often very great, sometimes exceeding 8 per cent., while the total elimination may exceed 500 gm. in twenty-four hours. It may be absent temporarily. Acetone is generally present in advanced cases. Diacetic acid may be present, and usually warrants an unfavorable prognosis. {139} CHAPTER III THE BLOOD